I now use four 150 watt bulbs in conjunction with the Bingham’s thermostat because it is quieter.
When I first started making glass bows I used a hair dryer turned on full to full heat and placed it at the end of an insulated box, with a hole at the other end to allow the air to flow. If your wife has an old hair dryer, this might be the fastest and least expensive method to make a heat box. My oven thermometer said it was 165 degrees at the center of the box. That would probably vary with the size of the box and make/type of hair dryer.